Many types of materials are often transported in bulk in vehicles or transportable containers. For example, for many years, granular materials such as sand, gravel, and dirt, as well as brush and tree trimmings, have been carried in the cargo areas of pickup trucks and other vehicles. Also, more recently, considerable attention has been given to transporting bulk cargos such as dry bulk chemicals, powdered and pelletized resins, flour, coffee beans, and grains in large intermodal cargo containers.
Many procedures are well known and widely used for loading and unloading bulk cargos into and out of cargo containers. Nevertheless, it is believed that these procedures may be improved. For example, in many cases it is difficult to pack a bulk cargo tightly in a vehicle or container, and, as a result, the cargo is packed relatively loosely, or at a relatively low density, in the container. Because of this, the container is not filled with the maximum amount of cargo that the container could be used to carry.
In addition, in many instances, unloading a bulk cargo from a vehicle or container is a difficult and time-consuming task. For example, many cargo containers are tilted to slide a bulk cargo out of the container under the force of gravity. However, many bulk cargos, such as flour, starch, and cement, do not easily or completely flow out of tilted containers under the influence of gravity alone, and often it is necessary for an individual to help force the cargo out of the containers--for example, by sweeping, agitating with vibrators, or shoveling the cargo outward.